From f3e226d8e89278a25303ce0c9e3693f30b0e53d6 Mon Sep 17 00:00:00 2001
From: Cassie Jones <code@witchoflight.com>
Date: Mon, 17 Feb 2020 12:05:01 +0100
Subject: [PATCH] Move the terms out into a separate file

The term is essentially purely user syntax, and has a decent chunk of
trait implementation boilerplate. It's nice to split it out from the
main chunk of the algorithm.
---
 src/lib.rs  | 63 +++--------------------------------------------------
 src/term.rs | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 60 deletions(-)
 create mode 100644 src/term.rs

diff --git a/src/lib.rs b/src/lib.rs
index ad587d1..4c84efb 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,66 +1,9 @@
 use dyn_clone::{self, DynClone};
 use im::{HashMap, Vector};
-use std::{fmt, sync::Arc};
+use std::fmt;
 
-#[derive(Clone, Copy, PartialEq, Eq, Hash)]
-pub struct Var(u32);
-
-#[derive(Clone, PartialEq)]
-pub enum Term {
-    Var(Var),
-    Pair(Arc<Term>, Arc<Term>),
-    Lit(i32),
-}
-
-impl From<&Term> for Term {
-    fn from(term: &Term) -> Term {
-        term.clone()
-    }
-}
-
-impl From<i32> for Term {
-    fn from(i: i32) -> Term {
-        Term::Lit(i)
-    }
-}
-
-impl From<Var> for Term {
-    fn from(var: Var) -> Term {
-        Term::Var(var)
-    }
-}
-
-impl fmt::Display for Term {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            Term::Var(v) => write!(fmt, "{:?}", v),
-            Term::Pair(l, r) => write!(fmt, "({}, {})", *l, *r),
-            Term::Lit(i) => write!(fmt, "{}", i),
-        }
-    }
-}
-
-impl fmt::Debug for Term {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        write!(fmt, "{}", self)
-    }
-}
-
-impl fmt::Debug for Var {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        write!(fmt, "x{}", self.0)
-    }
-}
-
-impl<T, U> From<(T, U)> for Term
-where
-    T: Into<Term>,
-    U: Into<Term>,
-{
-    fn from((t, u): (T, U)) -> Term {
-        Term::Pair(Arc::new(t.into()), Arc::new(u.into()))
-    }
-}
+pub mod term;
+pub use term::{Term, Var};
 
 #[derive(Debug, Clone, Default)]
 pub struct State {
diff --git a/src/term.rs b/src/term.rs
new file mode 100644
index 0000000..5a7f80f
--- /dev/null
+++ b/src/term.rs
@@ -0,0 +1,61 @@
+use std::{fmt, sync::Arc};
+
+#[derive(Clone, Copy, PartialEq, Eq, Hash)]
+pub struct Var(pub(crate) u32);
+
+#[derive(Clone, PartialEq)]
+pub enum Term {
+    Var(Var),
+    Pair(Arc<Term>, Arc<Term>),
+    Lit(i32),
+}
+
+impl From<&Term> for Term {
+    fn from(term: &Term) -> Term {
+        term.clone()
+    }
+}
+
+impl From<i32> for Term {
+    fn from(i: i32) -> Term {
+        Term::Lit(i)
+    }
+}
+
+impl From<Var> for Term {
+    fn from(var: Var) -> Term {
+        Term::Var(var)
+    }
+}
+
+impl<T, U> From<(T, U)> for Term
+where
+    T: Into<Term>,
+    U: Into<Term>,
+{
+    fn from((t, u): (T, U)) -> Term {
+        Term::Pair(Arc::new(t.into()), Arc::new(u.into()))
+    }
+}
+
+impl fmt::Display for Term {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Term::Var(v) => write!(fmt, "{:?}", v),
+            Term::Pair(l, r) => write!(fmt, "({}, {})", *l, *r),
+            Term::Lit(i) => write!(fmt, "{}", i),
+        }
+    }
+}
+
+impl fmt::Debug for Term {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(fmt, "{}", self)
+    }
+}
+
+impl fmt::Debug for Var {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        write!(fmt, "x{}", self.0)
+    }
+}
-- 
2.47.0